DOVER — A Dover man charged with strangling Elizabeth Marriott to death allegedly told police he killed her during the course of a consensual sex act involving erotic asphyxiation.

Thirty-year-old Seth Mazzaglia, of Dover, is facing first- and second-degree murder charges in connection with Marriott's death. He is accused of strangling Marriott with a rope inside his apartment on Mill Street on Oct. 9, 2012.

Police say after initially lying about the encounter, Mazzaglia admitted to his involvement during an interview at the Newington Police Department on Oct. 12, 2012. His statements to police were recounted in a police affidavit attached to an arrest warrant in the case.

The affidavit was among hundreds of pages of information unsealed Monday at the circuit court in Dover. Foster's Daily Democrat, the New Hampshire Union Leader and The Portsmouth Herald petitioned the court for access to the records, which had remained shielded from public view for more than six months.

The release followed Mazzaglia's indictment on murder charges in April by a Rockingham County grand jury.
According to the search warrant affidavit, Sgt. Joseph Ebert of the New Hampshire State Police Major Crime Unit questioned Mazzaglia on Oct. 12. Mazzaglia initially recounted a “variety of stories” about how Marriott died, according to the affidavit, all of which involved BDSM (bondage sadomasochism) exploration “gone too far.”

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Elizabeth Marriott

In one early version of the story, Mazzaglia allegedly told police he arrived home on Oct. 9 and “immediately sensed something was wrong.” Mazzaglia claimed a Rochester couple was present, as well as his live-in girlfriend, Kathryn McDonough, and Elizabeth Marriott. Mazzaglia said he remembered seeing a line across Marriott's throat, and said he believed that “someone had used their hands to manually strangle her,” according to police.
He later allegedly admitted to using a rope to strangle Marriott himself during what he described as a consensual sex act. Mazzaglia said he was playing strip poker with Marriott and his girlfriend on Oct. 9 when the three of them began talking about BDSM, according to the affidavit. Mazzaglia said the conversation “eventually led to a consensual sexual encounter involving autoerotic asphyxiation.”
Mazzaglia told investigators he put a rope around Marriott's neck while he was having intercourse with her, and applied pressure to the rope, according to the police affidavit. At some point, Mazzaglia said McDonough also became involved, but it was Mazzaglia who was tightening the rope before Marriott's death.

Mazzaglia said Marriott suffered what he described as a seizure. Mazzaglia said he then checked her body for a pulse in multiple locations and placed a plastic grocery bag over her head. Neither Mazzaglia nor McDonough rendered medical aid, according to an affidavit, despite the fact that both had formal medical training.

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Kathryn McDonough

Rochester couple questioned

On Oct. 12, police also interviewed a Rochester couple named Roberta Gerkin and Paul Hicock. Gerkin told police she received a call from the cell phone of Mazzaglia, whom she knew as “Lex,” at 10:49 p.m. on Oct. 9, according to court documents. Gerkin said it was McDonough on the phone, asking her to travel to Dover.
Hicock accompanied Gerkin, and when they arrived, they saw “a female subject lying unconscious on the living room floor,” according to a police affidavit. Gerkin described the woman to police as a white female with shoulder length brown hair, approximately 5 feet 6 inches tall. The woman was clothed only in a pair of blue underwear, and there were brown plastic grocery bags covering her head and face, Gerkin told police.
Gerkin said she used a box cutter to remove the bags, and observed the woman had a “blue face” and appeared to be dead, according to the police affidavit.

Gerkin claimed that “Lex” and McDonough then discussed “dumping the body,” but Gerkin wasn't specific about the exact statements she heard, according to the police affidavit.

Hicock recounted that “Lex” told him he had “blacked out” and stated something along the lines of “this time I went too far,” according to the affidavit. Hicock also recalled hearing a reference to “dumping the body.”

Trip to Portsmouth

Investigators say Mazzaglia accompanied State Police Sgt. Joseph Ebert and another detective to the location in Portsmouth where he allegedly deposited Marriott's body into the Piscataqua River. Mazzaglia said he “purposefully took back roads” from Dover to Portsmouth to “evade detection,” according to the police affidavit.

Mazzaglia led police along a footpath adjacent to the shipyard along the riverbank, in an area he described as “the grotto,” according to the police affidavit. It had a large concrete pad, surrounded by a black metal fence. Mazzaglia said he flipped Marriott's body over the fence and it landed on the ground on the other side. He then threw her body off a small cliff into the water. He also allegedly threw her cell phone into the water.

When Marriott's body did not entirely submerge, McDonough “completed the task,” and afterward, made a joking reference to “Davey Jones's locker,” according to an affidavit filed by Dover Police Sgt. Scott Pettingill.

Mazzaglia allegedly said he and McDonough then traveled to the Residence Inn at 1 International Drive in Portsmouth and discarded trash bags and an opaque tarp used to transport Marriott's body in a dumpster behind the hotel.

The pair then allegedly drove Marriott's car to the UNH parking lot on Mast Road in Durham. Mazzaglia told police they left on foot, carrying Marriott's clothes and pocketbook in plastic bags. According to the affidavit, Mazzaglia said they discarded some of the possessions in a dumpster behind the UNH horse barn, then discarded the remainder at a dumpster located between Village Pizza and Libby's.

Mazzaglia allegedly told investigators they also threw away gloves in various trash cans on a walk back to the Sawyer Mill Apartments in Dover. They arrived back at Mazzaglia's apartment at 1 Mill St. at about 6:15 a.m., according to Mazzaglia's account.
They then allegedly took the clothes they had been wearing, including Mazzaglia's boots, and put them in a white trash bag, which was discarded in dumpster behind the apartment complex.

Later in the morning, the two had sexual intercourse, as “McDonough was excited about what had happened the evening before with Ms. Marriott,” Pettingill's affidavit states.

McDonough claims cemetery visit

On Oct. 12, McDonough was interviewed by Sgt. Jeffrey Ladieu and Sara Hennessey of the N.H. State Police Major Crime Unit.

McDonough said Marriott was planning to visit her at 9 p.m. on the night Marriott disappeared. McDonough told police she was planning to take Marriott to a local cemetery to photograph ghosts.

In an interview with police, McDonough allegedly said she searched around the outside of the apartment complex for Marriott, and also checked at a local convenience store. McDonough told police she went to Pine Hill Cemetery alone, and recalled hearing strange noises. She told police she presumed Marriott was trying to scare her.
McDonough claimed her cell phone had died while she was inside the cemetery, and that she deleted the photos she shot that evening with her “cheap” camera, after uploading them to a computer.

McDonough claimed she only became aware of Marriott's disappearance after viewing information about it on Facebook the following morning, according to an affidavit.

Police search phone records, online ads

On Oct. 24, the state received warrants to search for the cell phone records and cell tower information for Mazzaglia, McDonough, Gerkin and Hickok's cell phones. Their providers included Verizon, Sprint and AT&T.

Police claim Mazzaglia, who was listed in McDonough's phone as “Darkheart,” sent text messages to his girlfriend in August setting out in “graphic detail” her role “as a submissive and his role as a dominant in BDSM sexual acts.”“Mazzaglia also discusses performing sexual acts on a friend of McDonough's while McDonough watches,” the police affidavit states, “and/or having McDonough (choose) a friend that she would 'offer' to Mazzaglia. Mazzaglia would then do 'anything' with her while McDonough watched.”

Police allegedly uncovered a number of text messages between McDonough and someone with the first name “Andi” between Oct. 7, 2012, and Oct. 11, 2012. In the messages, the pair discussed “the bondage sadomasochistic (BDSM) lifestyle,” according to a police affidavit attached to the search warrant for the phones.

They also allegedly discussed the prospect of Andi and her boyfriend participating in a “non-specified sexual encounter” at Mazzaglia's apartment, according to the affidavit. The encounter was slated for “sometime during the week of October 8, 2012.”

A co-worker at Target in Greenland told police McDonough's Facebook profile picture changed on Oct. 9 “to what he described as a weird and scary photo of McDonough dressed as a vampire with blood dripping from her mouth.”

Police later interviewed a woman they believe to be “Andi,” the woman with whom McDonough was corresponding via text message. According to the police affidavit, the woman confirmed she and her boyfriend were planning to visit Mazzaglia's apartment on Oct. 9, but they changed their plans, and instead went on Wednesday, Oct. 10.

The woman told police she was unaware Marriott had visited the apartment one day earlier, according to the affidavit. Her boyfriend said they played video games at the apartment and left.

The woman also pointed police to an online account she believed the couple had posted on a fetish and BDSM website. The advertisement stated they were seeking a “submissive” who would live with them. She told police McDonough used the screen named “roguetemptress” and Mazzaglia used the handle “enigmaticshadows.”

Police were unable to find any record of outgoing calls on McDonough's phone logs between Oct. 1 and Oct. 10. Investigators believe she deleted the records, based on information they tracked down in Marriott's cell phone history, according to an affidavit.

Cellmate reports possible 'code' letter

On Nov. 13, Dover police and state prosecutors attended a meeting with a Strafford County House of Corrections inmate and his lawyer. The man was awaiting trial on federal charges, according to a police affidavit.
The man said he shared a prison cell with Mazzaglia in the jail's medical unit. During that time, Mazzaglia allegedly told him that Marriott died during a “three way.” The inmate also told investigators Mazzaglia recalled that he blacked out during the episode, and when he came to, he was having sex with Marriott, who was having a seizure.

The inmate also claimed that Mazzaglia asked him to deliver a letter to McDonough after the inmate was released from jail. Mazzaglia allegedly provided his cellmate with a hand-drawn map of the route to the home of McDonough's mother.

“(The inmate) stated that he asked Mazzaglia what the letter said, and Mazzaglia stated that the letter outlined for McDonough the code that they can speak in over the telephone so that the police and investigators will not know what they are discussing,” reads a police affidavit.

Friend records conversation with McDonough

According to newly unsealed court documents, Roberta Gerkin met with McDonough on Dec. 22 and recorded their conversation.
McDonough allegedly admitted during the conversation that she was engaged in sexual activity with Marriott and her boyfriend on Oct. 9, and that the encounter involved a rope, according to an affidavit supporting a search warrant for phone records.

“McDonough also stated in substance that Ms. Marriott's death appeared to be accidental at first, but then turned 'purposeful,'” the affidavit states.

McDonough was arrested a few days later. She was indicted by a Rockingham County grand jury in April on charges of witness tampering, hindering apprehension or prosecution and conspiracy to do the same. Prosecutors have accused her of trying to cover up Marriott's death and trying to persuade Gerkin to lie to police.